Forming sheet glass



Dec, 15, i925- 1565.319

A. E. FOWLE FORMING SHEET GLASS Original Filed Feb. ll. 1924 VVE/Wax"J Aff/Wim@ Br Arm/:wr f

I 4Patented Dec. 15, -1925.

Unirse srarss PATENT; 'ovrriefnA ARTHUR E. FOWLE, OF TOLEDO, OHO, ASSIGNOR TO THE LIBBEY-OWENS SHEET GLASS COMPANY, OF TOLEDO, OHIO, A- CORPORATION OF OHIO.

FORMING SHEET GLASS.

Application filed February i1, 1924, Serial No. 691,941. Renewed February`26, 1925.

. i To all 'whomezf` may concern: Be it-known that l, ARTHUR E. Fowiln,

-a citizen of the United States, residing at Toledo, in the county lof Lucas and State of Ohio,have invented new and useful Improvements in Forming .Sheet Glass, of which the following is a specification.

This invention relates to an improved method and apparatus for producing sheet drawndownwardlg.7 therefrom. The stream 'forated -gas pipes l1,0 extending paraifel to..-

the sides ofy stream .8, are positioned below 80 glass by flowing glass downwardly trom a pool of molten glass.

In one form of sheet glass producing apparatus heretofore suggested, a stream of molten glass is flowed downwardly onto the top of a wedge-shaped slab, the top of the slab preferably being provided with a recess or depression for receivingr the molten stream. The glass overflows from' this re cess =in thin even films or streams down the converging outer sides of the slab, the streams uniting at the lower edge of the slab to form-a single glass sheet which is of molten glass which is received on the upper end of the slab flows through a slot or orifice in the bottom of the receptacle or hopper containing the' molten pool. Whenever glass is flowed through a slot or orifice,

unless the glass is in a highly heated fluid condition deposits of cold stringy glass are apt to form. Ialong the edges of the slot which produce lines or variations in the su rfaces of the flowing stream and hence in the surfaces or' the sheet resulting therefrom.

If the molten glass is heated to a suliciently high temperature to avoid the conditions noted above, it will become too fluid :lor the 'subsequent slieet-forniing process.

According to this invention, heating means'are directed against the surfaces of the stream of glass as it emerges from the -slot in the containing receptacle. This glass will properly adhere to and flow down the si es of the directing slab.

'.,lhe objects and 'advantages'o-the inven.

toh will be more fully iindetoodfrom the followingdetailed descriptlgnb. me A proved form of the Bl-,am

tank furnace in which th'e molten glass 2 60 is produced. As here shown the molten glass flows into a shallow tank or refining chamber 3 having a transverse slot 4 in the bottoni thereof through which a' portion of the molten glass flows downwardly. 1f de- 65 sired, this slot could be placed directly in the bottom or" the refining tank 1, although the shallower extension is preferable as it reduces the working head of glass above the slot. y

A short distance below slot 4f the slab or directing member 5 is suspended within the heated chamber 6. This chamber 6 has an open slot 7 in its upper wall-through which the stream of molten glassB flows down into the longitudinally extending recess 9..in the top of slab 5. 1 j A pair of heaters, here shown asper-l stream of molten glass reducing it .to such a fluid condition that no cold glassv canl form along,r the edges of slot 4. Obviously, electric heatersor other heating means could be substituted for the gas flames.

This highly heated fluid glassis caught in 90 -the recess 9 inthe to of slab 5 from which it flows evenly over t e upper side edges 12- of the slab. The molten glass must be sufficiently fluid to flow freely downc the outer side walls of the slab inthe*` crm of 4thin 95 films 13, but it must Vnot be tooluid else it will not adhere properly to these inwardly converging Aside Walls. Forl the purpose of somewhat reducing'the,temperature of the molten glass received -in receptacle `9, so that 190 it will be in the proper condition to flow down the sides of the slab, a pair of coolers lll are positioned within chamber 6 adjacent the upper' edges 120i the slab. These coolers may be in the form of hollow metallic casings or shields through which a constantlv renewed supply of 'water or-other cooling liuid is adapted to flow.

The films oit-streams of molten Y glass -13 flow down the side walls offslab 5 Within o here shown. Preferably, tburners 17 are po glass flows -in-thinpl-'ms or streams, cooling glaxss `a receptacle, for molten .glass having-a thc heated chamber 6 and unite at the lower edge of the slab as at 15 to form the single sheet of glass 16 which isdrawn downward ly,v preferably into the open air, 'by any suitable form of drawing mechanism, not

as 14, for again restoring the fluid glass to a proper workingtemperatur@` remove one main source of surface defects in the glass sheet, namely, the accumulation of cold lass along Athe edges of the slot through W ich the molten glass emerges from the tank.. Claims:

.1. The method ofproducing sheet glass, consisting in flowing a stream of molten glass downwardl from a container, highly heating the sur aces of the stream as 1t emerges from the container, catching `the molten glass on the upper end of a directing member down the outer sides of which the glass flows in thin rfili'ns or streams, `and cooling the molten streams as they overow the upper edges of the directing member.

2.' The method of producing sheet glass,y

consisting in'owing a, stream -of molten glass downwardl from 'a container, highly heating the sur acesof the stream as it emerges from the. container, catching the molten glass on the upper andof a directing member downthe Youterv sides of which' the the molten strams'as-theyov'erfiow the up per edges ofgthe'directing member, and reheating thgm'glten streams as the near the lower edge-0E the directing'. mem v r, where .the streams'arehmited-and' drawn' away inV the form of a'single 'glass sheet.

'1l-3.111 ani apparatus for yproduca sheet glass,` a. receptacle for molten glass aving axslot or orice 1n the! bottom thereof .through which a. stream o f molten glass may flow, means for directly" applying heat to thesurfacesof this stream as'it eaves the slot, a slablpositioned'below the slot having an u per surface for receiving the uid'glass 'whic fgw's therefrom; in thin film form down the'gconverging Aouter sides of the slab,

and-'nieans'for cool; the duid-glass as it over-owsthenpperlg es of the slab, 4; an apparatus .for producing' sheet slot or .orifice 4in theibtto'mthereof through v r'which a stream of olteniglass `may flow,

:im fus'p'ftlns streamas itileaves the slot-,a

means 'for directly' applying heat to the surslab positioned below 'the -slot having a lonl gitudinal recess, in its upper end for receiving the fluid glass which flowstherefrom inV thin film form'down the converging outer sides ofthe slab, and ineans for coolingthc fluid glassas vit overflows the upper edges of the slab.

j 5. In an. apparatus for producing sheet glass, 'a receptacle for molten glass having a slot or orifice in the bottom thereof through which a stream of molten glass may flow, means for directly applying heat'to,tlj1e surfaces of this stream as it leaves the slot, a

slab positioned below the slot having a longitudinal recess in its upper end for receiving the fluid glass which fiows therefrom in thin film form down the converging outerv sides ofthe slab, means for cooling the fiuid glass as it'overows the upper edges of the slab, the downwardly flowing glass films uniting at the lower edge of the slab to form a single sheet of glass, and means for reheat- 'ing the. films `adjacent the lower edge of the slab.

j ,6.A In an apparatus for producing sheet glass, a receptacle for molten glass having a 'slot or orifice in the bottom thereof through which'a stream of molten glass may fiow,

4means for directly applyin heat to the sur-j faces .of this stream as it eaves the slot, a

slab positioned below the slot having an upper surface for receiving the uid glass which fiows therefrom in thin film form down therconverging outer sides of the slab, and a pair of water-cooled shields positioned adjacent the sides of the slab for cooling the 'fiuid glass as it flows over the upper edges of the slab.

7. In an viapparatus for producing sheet glass, a receptacle for molten glass aving a slot or rifice in the'bottom thereof through which a stream of moltenA glass may ow,

means for-.directly applying heat to th 't surslab positionedybelow the slot havinga 1on1 gitu'dinal recess in its upper end for receiv- A ing he Huid glass which flows therefrom in thin film forrndown the converging'outer sides of the slab, and a pair of Vwater-cooled shields positioned adjacent the sides of theif slab for cooling'the `fiuid glass as it ows over. the upperedges of the slab.

8. The-method of producing sheet glass, consisting vinfiowing afstream of molten glass vdownwardly from a container, catching 'the molten glass on the upper "end ofa directing member down the outer sides tainer'to the directing member, and drawing faces of; this stream, as it leaves the s ot, a

of which the glasslows in thin films, highfly heating the. glass as it flows from the conthe thin'lmsfromthe end ofthe directing lmember in united-sheet form.

9. 'In' sheet glass apparatus,` a receptacle for' molten glass having a slot or orifice thereinthrough which'a stream of moltep glass flowing down -formymeans for absorbing heet from each lm as it flows down the side of glassows, a slab, positioned below the slot for receiving molten lass therefrom, the bef/n sides 01"' the slab in thin film the slab, and means 'for oli'awing the lms from the end of the slab in united sheet form.

10.' In sheet glass apparatus, a receptacle for molten glass having means to. permit a flow of glass therefrom, ay slab'positionecl '111 the path of die flow 01': glass to catch the same and. to Cause it to flow down both sides thereof in thin film formation, means for heating the strream as'it passes from the container to the slab, mii means t0 draw @he thin lms from the end of the slab in united sheet form.'

' Si ned at Toledo, in the county of Lucas f and tate of Ohio, this 8th day of Eebinaryjgo- 1924. ARTHUR E. FQWLE. 

